Objective To evaluate the immunogenicity and safety of inactivated poliovirus vaccine derived from Sabin strain (sIPV) in Banna mini pigs, and to provide experimental evidence for the new animal model. Methods sIPV vaccines which are listed at Institute of Medical Biology at Chinese Academy of Medical Sciences were used in this study. The groups of intramuscular sIPV and the wild strain IPV injections (IPV derived from wild strain, wIPV) were designed, and the saline group was used as a negative control group. The Banna mini pigs in various groups were immunized at 0, 1 and 2 months. Blood samples were collected before immunization and on days 30 after each immunization. Levels of neutralizing antibodies were tested for evaluating immunogenicity. The safety was evaluated by observation of the status and weight of mini pigs. Results After the three dose immunization schedules in the Banna mini pigs, the seroconversion rates of type Ⅰ,Ⅱ and Ⅲ sIPV experimental groups and wIPV group were all up to 100%. The neutralizing antibody levels in all the three types were much higher than the protective titer 1: 8. The weight of mini pigs increased after vaccination. Conclusions The sIPV vaccine has good immunogenicity and safety in Banna mini pigs. Banna mini pigs could be a new animal model for evaluation of sIPV vaccine.

Objective: To construct influenza B virus Vero cell adapted strain by genetic recombination technology by using the influenza B virus Vero cell adapted strain as the parent strain. Methods: The chick embryo and Vero cell were co-infected with influenza virus Vero cell adapted strain B/Malaysia/2506/2004 Va (Bv) and the vaccine strain B/massachusetts/2/2012 (BX-51B) recommended by WHO. The reassortants were screened with the anti-Bv serum. Plaque-purified reassortants were used to screen for Vero cell-adapted influenza B virus strains containing the surface antigen of the epidemic strain. Results: A Vero cell-adapted influenza B virus strain was obtained with successive passage in Vero cells. The hemagglutination inhibition test and the one-way immunogold agar diffusion test both showed that the reassortant virus was homologous to NYMC BX-51B, and sequence analysis result showed that the reassortment virus has the same HA and NA gene with the vaccine strain. Conclusion B/Malaysia/2506/2004Va (Bv) can be used as a parent strain to prepare Vero cell vaccine against influenza B virus.